1. Field of the Invention
The present invention relates to an electronic device such as PDA (personal digital assistants) or cellular phone with an image pickup function and an authentication system for carrying out individual authentication based on a fingerprint image read by the electronic device with the image pickup function.
2. Description of the Related Art
In recent years, connection to Internet using a portable electronic device such as PDA or cellular phone and an access to a desired Web site are frequently carried out.
Such access processing over Internet often requires authentication of identity because of a security problem. Authentication of identity due to check a single ID code or personal identification number for coincidence has low reliability, and an identity authentication based on fingerprint is desired.
On the other hand, there is provided a conventional portable terminal device with an image pickup function. For example, the PDA or cellular phone includes a small sized CCD (charge coupled device). However, in such a portable terminal device with an image pickup function, if an attempt is made to pick up a fingerprint image, a plurality of optical systems that differ from each other during ordinary imaging and fingerprint imaging are disposed, and these systems must be used by switching them. The makes it difficult to provide a configuration suitable to miniaturization.
Meantime, in fingerprint authentication, in order to ensure a certain degree of authentication precision, it is required to sample a predetermined number of characteristics graphics (for example, less than 13) from fingerprint data. In any of registered fingerprint data and authentication fingerprint data as well, it is required to sample a fingerprint image in a region close to the substantially entirety of fingers. Thus, it is difficult to apply to a fingerprint authentication system a partial fingerprint image sampled from a portable terminal in which only a small fingerprint reading window can be provided.